Cu²⁺ Modified Silicalite-1/NaY Structure for the Adsorption Desulfurization of Dimethyl Disulfide from Methyl tert-Butyl Ether

Abstract

Selective adsorption desulfurization of dimethyl disulfide (DMDS) from methyl tert-butyl ether (MTBE) has been studied on the silicalite-1/CuY core–shell composites. Different copper ion sources (CuCl2, Cu­(NO3)2, and CuSO4) were investigated to form CuY as the core by Cu2+ ion-exchange on NaY zeolite. These silicalite-1/CuY core–shell composites were synthesized at the mass ratio of tetraethyl orthosilicate (TEOS)/tetrapropylammonium hydroxide (TPAOH)/ethanol/H2O/CuY = 20 g:19 g:17 g:87 g:5 g. Results showed that the core–shell Y-CuCl2 displayed the best performance in desulfurization of DMDS with a sulfur adsorption capacity of 32.882 mgs/gadsorbent, owing to its significant mass gain and compact coatings after being coated by silicalite-1 on Y-CuCl2. Also, the preparation process of CuY and the shape selective adsorption mechanism of desulfurizing DMDS from MTBE on the silicalite-1/CuY core–shell composites were expounded.

Selective Adsorption of Dimethyl Disulfide on Acid-Treated CuYH@Silicalite-1 Core–Shell Structure: Methyl tert-Butyl Ether as a Competition Component

“…Lee et al investigated desulfurizing DMDS in C4 hydrocarbon mixtures with β zeolites and claimed that Cu­(I) ion-exchanged zeolites showed high DMDS capacity of 8.70 mg s /g adsorbents . Nevertheless, when adsorbing DMDS in MTBE, there would be a fierce competition between them on π-complexation adsorbents, which has been detailedly described in the previous studies, − and Yang et al , had claimed that the adsorption capacity of sulfur on π-complexation adsorbents decreased sharply in the presence of MTBE. To solve the competitive adsorption, by using modified ZSM-5 zeolites, Zhao et al had tried to adsorb DMDS from MTBE and acknowledged that the pore structure and acidity both played key roles in the adsorption process and reached a not too optimistic adsorption capacity of 8.24 mg s /g adsorbents .…”

“…15,16,29 Previously, we have applied a core−shell structured composite with NaY whose structure is shown in Scheme 2 with CuY as the core and silicalite-1 as the shell to remove DMDS in MTBE solution and obtained an adsorption capacity of sulfur on NaY@silicalite-1 and CuY@silicalite-1 to be 20.711 and 32.882 mg s /g adsorbent , respectively. 21,22 In the present study, we are trying a new way in synthesizing core−shell composites by the dealuminization of HCl on Y zeolite to obtain a better growth environment for the silicalite-1 shell. Dealuminization is an efficient method to increase the ratio of Si/Al by transferring framework Al into an extra-framework position and then being washed away.…”

Adsorption of toluene on silicalite‐1/NaY composites: Influence of NaY pretreatment on hydrophobic properties

“…Many literatures had reported coating silicalite-1 on different types of zeolites. [22][23][24][25] However, the hydrophobicity of the silicalite-1/NaY composites and the adsorption properties of VOCs in a humid environment had rarely been investigated. In this paper, before the silicalite-1/NaY composites were synthesized, NaY was treated by different pretreatment (HCl and NaOH).…”

Desulfurization through Photocatalytic Oxidation: A Critical Review

“…The former two methods can be performed under mild conditions, such as relative low temperature and ambient pressure. For instance, adsorption desulfurization (ADS), a promising physical technology using zeolite, [6,7] metal organic skeleton, [8] or metal and metal oxide as adsorbents [9,10] to achieve deep desulfurization (sulfur content <1 ppm), has advantages of simple manipulation as well as economic and environmental benignity [11] . Although ADS can obtain ultra‐high desulfurization efficiency, its adsorption capacity and adsorbent regeneration are rather limited [12] .…”